Abstract.
Ribokinase (RK) and adenosine kinase (AK) catalyze the phosphorylation of ribose and adenosine to ribose-5-phosphate and AMP, respectively. Belonging to the RK family of proteins, these enzymes share a number of unique structural and functional elements. Extensive work has been carried out on many aspects of these enzymes in recent years, and we summarize the wealth of information currently available on them. The topics covered include descriptions of the primary and three-dimensional structures of AK and RK, their phylogenetic relationships, biochemical aspects of these enzymes including their reaction mechanisms and ionic requirements, and also work on certain inhibitors of these enzymes. The cellular metabolism and transport of ribose and adenosine are also briefly discussed, as well as the beneficial effects of ribose and adenosine in physiology and how these effects can be harnessed for pharmacological purposes.
Keywords. Adenosine kinase, ribokinase, NXXE motif, gene structure and mutants, enzyme inhibitors, PfkB family of proteins, phosphate dependency, adenosine and ribose metabolism
Footnotes
Received 10 March 2008; received after revision 18 April 2008; accepted 22 April 2008